Electron microscopic study of intrastromal hydrogel implants in primates

Area of Science:

• Ophthalmology
• Biomaterials Science
• Corneal Research

Background:

• Intrastromal hydrogel implants are being explored for corneal applications.
• Assessing the biological response of the primate cornea to synthetic implants is crucial for clinical translation.

Purpose of the Study:

• To evaluate the tolerance of the primate cornea to intrastromal hydrogel implants (surfilcon A).
• To investigate the tissue response and potential biocompatibility of synthetic plastic corneal implants.

Main Methods:

• Three primate corneas with intrastromal surfilcon A hydrogel implants were analyzed.
• Techniques included penetrating keratoplasty, light microscopy, scanning electron microscopy, and transmission electron microscopy.

Main Results:

• Implants in the posterior cornea caused protrusion into the anterior chamber, visible clinically.
• Corneal tissue showed physiological stress, including epithelial thinning, irregular cell shapes, and vacuolations.
• Keratocytes produced a basement-membrane-like material at the implant-stroma interface, aiding tissue integration.

Conclusions:

• The primate cornea exhibits some physiological stress in response to surfilcon A hydrogel implants.
• No inflammatory reactions were observed around the implants.
• Further long-term studies are required to confirm the compatibility of these synthetic implants with corneal tissue.